Today, a storage system including a nonvolatile memory is widely used. One of such storage systems includes a NAND-flash-type solid state drive (SSD). The SSD is used as main storage of various computing devices for its low power consumption and high-speed performance.
The SSD is also widely used in a storage server. A storage server having a data compression function is developed in order to efficiently manage a large number of data and various kinds of data. The storage server having the data compression function compresses data to be written to the SSD, and sends a request for writing the compressed data to the SSD.
The length (data length) of compressed data is different from the length (data length) of uncompressed data (original data). In addition, the data length of the compressed data obtained by compressing the original data is different depending on the type of the original data. For that reason, the storage server needs to manage the compressed data length with respect to each piece of data, in order to access each piece of data stored in the SSD. This can cause increase in a burden of data management on the server side.